The present invention relates to a thin plate storage container, in which the load on the container body in transportation is reduced to improve sealing. The present invention further relates to a thin plate storage container for securely supporting a plurality of thin plates stored within the container body.
The transportable containers for containing and transporting semiconductor silicon wafers are generally known. In such a wafer container, it is important to keep its inside clean to prevent dirt and the like from collecting on the surfaces of contained semiconductor silicon wafers during transportation. For this purpose, the container is sealed tightly, usually by a sealing member on the lid of the container, which sealing member contacts the container body to seal it when the lid closes the container body.
In addition, the thin plate storage containers have a handle on each side of to be gripped for carrying by hand.
Semiconductor silicon wafers are stored in the in the above-mentioned containers for transfer to a semiconductor manufacturing factory and the like, where the container goes through a production line.
Moreover, it is necessary that the wafer container support the semiconductor silicon wafers at regularly spaced intervals to keep them from contacting each other. Therefore supporting members are placed on both the interior of the container body and on the interior side of the lid to support semiconductor silicon wafers at regularly spaced intervals.
An example of a supporting member incorporated into a lid is illustrated in FIG. 26. This supporting member is disclosed in Japanese TOKUHYOHEI No.4-505263. As shown in FIG. 26, an upper cover 35 has a holder 36 for supporting semiconductor silicon wafers from above, mounted on its inner side. The semiconductor silicon wafers 37 are stored in the container body (not illustrated) positioned below the upper cover 35.
The wafer holder 36 has supporting arm portions 38 alternately extending from right and left. Base ends of the supporting arms 38 are fixed to the interior side of upper cover 35, and the opposite ends extend toward the semiconductor silicon wafers 37. A holddown member 39 at the tip of each of the supporting arm 38 engages an edge portion of a semiconductor silicon wafers 37 to support each semiconductor silicon wafer 37 at regularly spaced intervals.
In order to manually lift and lower for transport and the like, a worker grips the handles to hold the thin plate storage container. However, since the handles are located on the sidewalls of the thin plate storage container, the sidewalls receive a load when the thin plate storage container is lifted, whereby the opening of the container body can be slightly distorted and the sealing member can slip slightly. This effect is undesirable although there is no problem with the sealing.
There is a slight gap between the container body and the lid when the container body is fitted with the lid. Although there is no problem in normal use of the thin plate storage container, there is the possibility that the thin plate storage container will receive a shock when the thin plate storage container is mounted in use. In this case, the lid can slip because of the gap between the container body and the lid and the sealing member will also slip. In such an event, although there is no sealing problem, the result is not the desired perfection.
Moreover, in the thin plate storage container having the above-described structure, each of the supporting arm portions 38 of the wafer holder 36 is cantilevered such that base end of the arm is fixed to the upper cover 35 and the distal end is free. The supporting arm portions 38 thereby hold the semiconductor silicon wafers 37 with a comparatively weak force, and it is difficult to strongly hold the semiconductor silicon wafers 37. Therefore, it is difficult to securely hold a semiconductor silicon wafer 37 of a large radius and heavy weight and there is the problem that the semiconductor silicon wafers 37 shake within the container.
Because the wafer holder 36 is cantilevered, i.e. each holddown member 39 pivots about its base, if the semiconductor silicon wafers 37 slip, there is the problem that friction is generated between the holddown members 39 and the semiconductor silicon wafers 37 and particulate matter thereby generated.